Except where specifically defined herein, all words used in this Code shall carry their customary meanings. Words used in the present tense include the future, and the plural includes the singular; the word “shall” is always mandatory, the word “may” denotes a use of discretion in making a decision; the words “used” or “occupied” shall be considered as though followed by the words “or intended, arranged or designed to be used or occupied.” Words used in the masculine gender include the feminine, and the feminine the masculine.